Senate Minority Leader Mitch McConnell's (R-KY) campaign manager said he's begrudgingly working in his current capacity to help the presidential prospects of Sen. Rand Paul (R-KY), according to an explosive phone recording that surfaced Thursday.

In the recording, obtained by Economic Policy Journal, Jesse Benton — who ran Paul's successful 2010 campaign before joining McConnell's team — told conservative activist Dennis Fusaro that he has an ulterior motive in working the GOP leader's 2014 campaign.

"Between you an me, I'm sorta holding my nose for two years," Benton said in the recording, "'cause what we're doing here is gonna be a big benefit to Rand in '16."

The call was recorded by Fusaro on January 9.

McConnell endorsed Paul's GOP primary opponent, Trey Grayson, in 2010. Paul, however, made it clear that he's backing McConnell in his re-election effort next year.

Benton pushed back forcefully, issuing a statement to denounce the recording and reiterate his commitment to McConnell's campaign.

"It is truly sick that someone would record a private phone conversation I had out of kindness and use it to try to hurt me," he said in the statement. "I believe in Senator McConnell and am 100 percent committed to his re-election. Being selected to lead his campaign is one of the great honors of my life and I look forward to victory in November of 2014."

Shortly after the story surfaced, McConnell's tea party challenger, businessman Matt Bevin, took to Twitter to needle the incumbent:

Even Mitch McConnell's campaign manager thinks Sen. McConnell isn't conservative and is holding his nose for 2 years #kysen...

There's still no word from state Secretary of State Alison Lundergan Grimes, the Democrat who's challenging McConnell, but the Democratic Senatorial Campaign Committee quickly made hay of the comment.

“Mitch McConnell is so unpopular in Kentucky that even his own campaign manager can’t stand him," DSCC spokesman Justin Barasky told TPM over the phone. "Unfortunately for McConnell, polls show that people of Kentucky won’t be holding their noses in 2014.”